921 research outputs found
Scaling study of Si and strained Si n-MOSFETs with different high-k gate stacks
Using ensemble Monte Carlo device simulations, this paper studies the impact of interface roughness and soft-optical phonon scattering on the performance of sub-100nm Si and strained Si MOSFETs with different high-k gate stacks. Devices with gate lengths down to 25nm have been investigated
Shaping cultural participation through social media
AbstractThe public sector has embraced a user‐orientation paradigm, which has expanded through the open and democratic medium of social media. Although the potential of this digital technology and its visible outcomes have been analyzed in previous studies, there is virtually nothing on the complexity behind its implementation. This paper uses a case study involving three Italian museums to explore how social media strategy is shaped and enacted through their day‐to‐day business and activity. Museums are an ideal field for this kind of research because of the central role played by cultural participation and social media's critical function in pursuing new audiences. The study reveals a deep change to practice, touching praxes and practitioner skills, and modifying strategies planned around the user's approach, in the duality between authoritative and democratic voices. The findings disclose an emergent heterogeneity that is mapped along social media practices and the various associations linked to the praxes, opening the way for future studies concerned with the link between a user's (traditional) physical experience on social media and the level of democracy in user engagement
Sero-prevalence of HIV among patients with cervical cancer managed at the Tikur Anbassa Hospital Addis Ababa, Ethiopia
Background: Cervical cancer is the second most common cancer among women in the world. Globally, according to the 2010 report, 493,243 women diagnosed with cervical cancer and 273, 505 of them died from the disease. It is also the commonest gynecologic cancer in the Ethiopian women. Ethiopia is one of the Sub- Saharan African countries with high HIV prevalence. Studies done in different parts of the world demonstrated clear association between HIV and premalignant cervical lesions but studies on HIV prevalence in invasive cervical cancer are few and showed a wide range of variations. Objective: To determine the sero-prevalence of HIV among patients with histologically confirmed cervical cancer in Addis Ababa, Ethiopia. Design: A facility based cross-sectional descriptive study. Setting: Tikur Anbassa hospital, Addis Ababa, the only comprehensive cancer treatment center in Ethiopia. Main variables: Prevalence of HIV, mean age, diagnosis of cervical cancer. Materials and methods: All newly diagnosed, and biopsy proven uterine cervical cancer patients who were managed at Tikur Anbassa hospital records were sought. The records were identified perused and those found to fulfil study entry criteria were evaluated and information collected using structured questionnaire. Data required from each study subject included; socio-demographic, reproductive characteristics and clinical information. Data was then pooled, screened and entered in SPSS. The results were computed and presented in the form of; tables and figures, mean with standard deviation and proportion for quantitative and qualitative statistic respectively. T-test for equality, Chi-square test, and logistic regression were used to measure associations. Significance level was set at P value of 0.05.Result: Of the 255 subjects studied, majority has late clinical stage and squamous cell carcinoma histologically, 64.7% and 92.5% respectively. Similarly,34 out of the 255 were positive for HIV, making the overall sero-prevalence rate of 13.3%. The mean age of the total study population was 46 ±10.55 years. Significant difference was observed in the mean age of cervical cancer occurrence for HIV infected cases compared to the non-infected, 37.01 ± 6.7 and 48.23±10.26 years, respectively (p=000). HIV status and CD4 count were not shown to have any association with clinical stage and histologic variants. Having more than one lifetime sex partner and age less than 40 years were independently shown to have significant association with HIV sero-positivity. Mean CD4 count of the HIV positive subjects was 442.2±251.27. Conclusion and recommendation: In this study HIV infected women with cervical cancer were 8 to 14 years younger than HIV- negative women with cervical cancer. The disease stage and histology were not different in both groups, and without evidence of advanced disease in immune compromised state. It is recommending that further larger scale multicenter study, to explore the reasons for the younger age of occurrence of invasive cervical cancer in patients with HIV/AIDS
Associations between physical fitness and adiposity among school-age children from Monteria, Colombia
Los niveles bajos de condición física se han asociado con adiposidad elevada. Ambas condiciones pueden predecir alteraciones cardiovasculares y metabólicas. El objetivo fue analizar la relación entre la condición física y los indicadores antropométricos de adiposidad. Estudio transversal, en 534 escolares de 6 a 12 años de edad del municipio de Montería. Se midió la condición cardiorrespiratoria (CCR), flexibilidad, fuerza explosiva de miembros inferiores (FEMI), fuerza resistencia abdominal (FRA), Índice de Masa Corporal (IMC), masa adiposa (PMA), y perímetro abdominal (PA). Las asociaciones entre adiposidad y la condición física se analizaron con modelos de regresión logística. Se encontró que el sobrepeso está asociado a baja CCR (ORa = 2,7, p<0,0001); el PA elevado está asociado a baja FRA (ORa = 2,2, p<0,02), y a baja CCR (ORa = 3,3, p<0,001); el PMA elevado está asociado a baja CCR (ORa = 2,7, p<0,0001). Conclusión, la condición física está asociada a la adiposidadLow physical fitness levels have been associated with elevated adiposity. Both conditions may predict cardiovascular and metabolic alterations. The objective was to analyze the associations between health-related physical fitness and adipose. A cross-sectional study in 534 school-age children aged 6-12 in Monteria, Colombia. Measurements included cardiorespiratory fitness (CCR), flexibility, explosive strength of lower limbs (FEMI), abdominal strength endurance (ASE), body mass index (BMI), percentage of adipose mass (PAM), and waist circumference (WC). The associations between adiposity and physical fitness were calculated by logistic regression models. Results indicate that overweight is associated with low CCR (aOR = 2.7, p<0.0001). Elevated PA was associated with low ASE (aOR = 2.2, p<0.02), and with low CCR (aOR = 3.3, p<0.001). Elevated PMA was associated with low CCR (aOR=2.7, p<0.0001). In conclusion, physical fitness is associated with adiposity
Electron transfer efficiency in liquid xenon across THGEM holes
Dual-phase liquid-xenon time projection chambers (LXe TPCs) deploying a few
tonnes of liquid are presently leading the search for WIMP dark matter. Scaling
these detectors to 10-fold larger fiducial masses, while improving their
sensitivity to low-mass WIMPs presents difficult challenges in detector design.
Several groups are considering a departure from current schemes, towards either
single-phase liquid-only TPCs, or dual-phase detectors where the
electroluminescence region consists of patterned electrodes. Here, we discuss
the possible use of Thick Gaseous Electron Multipliers (THGEMs) coated with a
VUV photocathode and immersed in LXe as a building block in such designs. We
focus on the transfer efficiencies of ionization electrons and photoelectrons
emitted from the photocathode through the electrode holes, and show
experimentally that efficiencies approaching 100 % can be achieved with
realistic voltage settings. The observed voltage dependence of the transfer
efficiencies is consistent with electron transport simulations once diffusion
and charging-up effects are included
Effects of Bisphenol-A and Styrene on Fertilization and Development of the Purple Sea Urchin (Strongylocentrotus purpuratus)
Plastic waste and debris have greatly increased in the marine environment during the past 50 years. Not only do these plastics entangle and get ingested by marine mammals, turtles, and sea birds, but they also leach chemicals, such as bisphenol-A (BPA) and styrene into the aquatic environment. While some of these chemicals are known to be toxic, few studies have examined their effects on broadcast spawning marine invertebrates, specifically at environmentally relevant concentrations. Purple sea urchins, Strongylocentrotus purpuratus, from the central coast of California, were utilized to examine effects of BPA and styrene on fertilization success and early development of resulting embryos. Previous research has demonstrated that BPA and styrene decrease successful fertilization and delay development of sea urchins, though no previous studies have examined effects of continuous chemical treatment on S. purpuratus development. We exposed eggs, sperm, or both to environmentally relevant concentrations of BPA or styrene (100 µg/L, 500 µg/L, and 1000 µg/L) to test the hypothesis that continuous treatment would lead to developmental abnormalities. The greatest effect was observed in pluteus larvae development, as the percentage of normal embryos decreased by as much as 80% in high dose chemical treatments (p
Controller Coordination Strategy for DC Microgrid Using Distributed Predictive Control Improving Voltage Stability
The paper presents the design and control strategy of an isolated DC microgrid, which is based on classical control techniques, predictive control and iterative algorithms. The design control parameters are maximum overshoot, settling time and voltage ripple. The strategy is designed to operate in two different modes, end-users minimum and maximum demand scenarios, and this is achieved through the incorporation of network dynamic loads. The control methodology developed allows to obtain a fast response of the design set points, and an efficient control for disturbance rejection. The simulation results obtained satisfy the proposed design guidelines by obtaining a maximum overshoot of 4.8%, settling time of 0.012 seconds and a voltage ripple of 0.1 percentage. The implemented system simulation was developed in Matlab-Simulink software
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